immunology of COVID19

Question 1

Briefly outline SARS-CoV-2

Answer 1

It is a +ve sense, single-stranded RNA virus
infects vertebrates and invertebrates
can use host cell proteins during rep and gene expression

Question 2

How do SARS-CoV-2 and related viruses enter the cell

Answer 2

The spike protein binds to plasma membrane proteins that facilitate cell entry such as ACE2, Furin etc which sets a cascade of events that causes fusion between the virus and the cell.

Question 3

How is tissue tropism determined in relation to the virus

Answer 3

Largely determined by ACE2 expression,

Question 4

describe the structure of the spike protein

Answer 4

2 sub units s1 & s2

s1 subunit contains a receptor-binding domain that recognizes and binds to the host receptor angiotensin-converting enzyme 2

the s2 subunit mediates viral cell membrane fusion.

Question 5

What is trained immunity

Answer 5

Result of firing up immunity by stimuli/ events that stimulate the same innate immune cells that protect us from infection
e.g. recent vaccination

in older people, innate immunity is reduced so they get more severe COVID-19